REV. 0

AD1981A

–22–

Vendor ID Registers (Index 7Eh)

Reg Num Name

D15 D14 D13 D12 D11 D10 D9 D8

D7

D6

D5

D4

D3

D2

D1

D0

Default

7Eh

Vendor ID2 T7

T6

T5

T4

T3

T2 T1 T0 REV7 REV6 REV5 REV4 REV3 REV2 REV1 REV0

5372h

T[7:0] This register is ASCII encoded to ‘S’

REV[7:0] Vendor-specific revision number: The AD1981A assigns 71h to this field.

Table II. Codec ID and External Clock Selection

ID1

IDO

CODEC ID

CODEC CLOCKING SOURCE

1

1

(00) PRIMARY

24.576 MHz (Local Xtal or External into XTL_IN)

1

0

(01) SECONDARY

12.288 MHz (External into Bit_Clk)

0

1

(00) PRIMARY

48.000 MHz (External into XTL_IN)

0

0

(00) PRIMARY

14.31818 MHz (External into XTL_IN)

Note that the ID# Pins have weak internal pull-ups and are inverted internally.